Creating Web Applications Using ASP.NET

guideflannelServers

Dec 4, 2013 (3 years and 9 months ago)

89 views

Creating Web Applications
Using ASP.NET

Chapter

Microsoft Visual Basic .NET: Reloaded

1

2

Microsoft Visual Basic .NET: Reloaded

Objectives


Define the terms used when talking about the
Web


Create a Web application


Add controls to a Web form


Start a Web application


Use the validator controls


3

Microsoft Visual Basic .NET: Reloaded

Objectives (
continued
)


Include a list box on a Web form


Determine whether a postback has occurred


Include a DataGrid control on a Web form


4

Microsoft Visual Basic .NET: Reloaded

Web Terminology


Internet


world’s largest computer network


WWW (World Wide Web)


Contains documents called web pages


Web pages are stored on Web Servers


Web Server is a computer with software to
serve up web pages in response to client
requests (web browser)

5

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


Static Web page displays
information to the viewer


6

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


HTML (Hypertext Markup Language)
tags tell browser how to display
information in page

7

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


URL (Uniform Resource Locater)


Unique address that identifies location of a
web page


URL contains 4 parts
:


http://
--

HTTP communication protocol


Protocol is agreement between sender and
receiver how data is sent and interpreted


Host
--

name of web server


Path
--

location of document on the web server


Document name



8

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


Dynamic Web page is interactive


It can accept information from the user and
also retrieve information for the user


9

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


Use Web Form Designer Window to create
web pages in Visual Basic .NET

10

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


Use HTML tab to view html code
automatically generated by the IDE

11

Microsoft Visual Basic .NET: Reloaded

Web Terminology (
continued
)


.aspx file contains controls and html


.aspx.vb file contains program code

12

Microsoft Visual Basic .NET: Reloaded

HOW TO…

13

Microsoft Visual Basic .NET: Reloaded

Creating Web Applications


Begin by starting a blank solution

14

Microsoft Visual Basic .NET: Reloaded

Creating Web Applications (
continued
)


Add a ASP.NET Web Application project to
the blank solution

15

Microsoft Visual Basic .NET: Reloaded

Creating Web Applications (
continued
)


IDE with web form in design view

16

Microsoft Visual Basic .NET: Reloaded

Creating Web Applications (
continued
)


Rename web pate (.aspx file) and set title
property

17

Microsoft Visual Basic .NET: Reloaded

Adding Controls to a Web Form


Similar to adding controls to a Windows form


Use tools contained in toolbox


Controls are not identical to Windows
counterparts


Have ID property rather than name property

18

Microsoft Visual Basic .NET: Reloaded

HOW TO…

19

Microsoft Visual Basic .NET: Reloaded

Adding Controls to a Web Form

(
continued
)

20

Microsoft Visual Basic .NET: Reloaded

Adding Controls to a Web Form

(
continued
)

21

Microsoft Visual Basic .NET: Reloaded

HOW TO…

22

Microsoft Visual Basic .NET: Reloaded

Starting a Web Application


Displays in external browser or in internal
browser built into Visual Studio .NET

23

Microsoft Visual Basic .NET: Reloaded

HOW TO…

24

Microsoft Visual Basic .NET: Reloaded

Using the Web Validator Tools


RequiredField validator



verifies control
contains data


RangeValidator



verifies data falls within
a set range of values

25

Microsoft Visual Basic .NET: Reloaded

HOW TO…

26

Microsoft Visual Basic .NET: Reloaded

Including a List Box on a Web Form

27

Microsoft Visual Basic .NET: Reloaded

Code for Stovall application

28

Microsoft Visual Basic .NET: Reloaded

Code for Stovall application

(
continued
)

29

Microsoft Visual Basic .NET: Reloaded

Stovall application (
continued
)


Page_Load event


Occurs first time web form is displayed


Also occurs when a postback action happens


Postback refers to client requesting data from
server


IsPostBack property indicates if form is being
displayed for first time or as a result of postback


30

Microsoft Visual Basic .NET: Reloaded

Stovall application (
continued
)


Sample run of Stovall Application

31

Microsoft Visual Basic .NET: Reloaded

Including a DataGrid Control on a Web
Form

32

Microsoft Visual Basic .NET: Reloaded

Including a DataGrid Control on a Web
Form

(
continued
)


Web application for Fairview Industries
connects to an Access database and
displays data in datagrid

33

Microsoft Visual Basic .NET: Reloaded

Including a DataGrid Control on a Web
Form

(
continued
)


Must call
DataBind

method to bind data to
datagrid

34

Microsoft Visual Basic .NET: Reloaded

Customizing the Appearance of the
Web DataGrid Control’s Data


Click datagrid control and then click Auto
Format link in properties list

35

Microsoft Visual Basic .NET: Reloaded

Customizing the Appearance of the
Web DataGrid Control’s Data (
continued
)


Sample run of Fairview application with
Datagrid formatted using Professional 2
scheme

36

Microsoft Visual Basic .NET: Reloaded

Programming Example


Monthly
Payment Calculator Application


Fred Pierce has been shopping for a new car
and has asked you to create an application
that he can use to calculate and display his
monthly car payment,


using annual interest rates of 5%, 6%, 7%, 8%,
9%, and 10%, and


terms of two, three, four, and five years


37

Microsoft Visual Basic .NET: Reloaded

TOE Chart

38

Microsoft Visual Basic .NET: Reloaded

User Interface

39

Microsoft Visual Basic .NET: Reloaded

Objects, Properties, and Settings

40

Microsoft Visual Basic .NET: Reloaded

Objects, Properties, and Settings

(
continued
)

41

Microsoft Visual Basic .NET: Reloaded

Pseudocode

Page Load event procedure


1.
if it’s the first time the Web form is

displayed



fill the lstRate control with data



fill the lstTerm control with data



select the first item in each list box


end if

btnCalc Click event procedure


1.
calculate the monthly payment


2.
display the monthly payment in lblPayment


42

Microsoft Visual Basic .NET: Reloaded

Code

43

Microsoft Visual Basic .NET: Reloaded

Code (
continued
)

44

Microsoft Visual Basic .NET: Reloaded

Summary


The Web consists of Web pages that are
stored on Web servers


A client uses a browser to request a Web
page from a Web server


Web pages can be either static or dynamic
(interactive)


Static Web pages contain the information to
display, as well as the HTML tags that control
the appearance of the information


Static Web pages are not interactive


45

Microsoft Visual Basic .NET: Reloaded

Summary (
continued
)


Every Web page has a unique address, called
a URL, that indicates its location on the Web



A URL consists of four parts: the protocol, the
name of the Web server, the path to the Web
page, and the name of the Web page


A Web server can be a remote computer or
your local machine


To make your local machine a Web server,
you must install and configure Microsoft IIS
(Internet Information Services)


46

Microsoft Visual Basic .NET: Reloaded

Summary (
continued
)


A dynamic Web page requires two files: one
ending with .aspx and the other with .aspx.vb


The .aspx file contains the controls and HTML
that define the Web page’s interface, and the
.aspx.vb file contains program code


You add controls to a Web form in the same
way that you add controls to a Windows form


The Web Forms tab in toolbox contains Web
tools


Web tools are similar but not identical to their
Windows counterparts


47

Microsoft Visual Basic .NET: Reloaded

Summary (
continued
)


You test a Web application using a browser


The Web Forms tab on the toolbox contains
five validator tools


Validator tools allow you to validate user input


You can use a Web form’s IsPostBack
method to determine whether the form is
being displayed for the first time